Omron CS1W-ETN21 operation manual Prohibiting Dynamically Changing Remote IP Addresses

IP Addresses in FINS Communications	Section 5-2
• Connection method:	FINS/UDP

•FINS Node Address Not Registered to IP Address Table The following address is registered to the internal table.

• Remote IP address:	Local IP address network number + FINS
	node address
• Remote UDP port number: UDP port number set for local Unit
• Connection method:	FINS/UDP

With the combined method, records of FINS nodes registered to the IP address table are not dynamically changed. For all others nodes, the data from FINS nodes registered with a remote IP address of 0.0.0.0 can be dynamically changed when the Unit is turned ON or restarted, according to FINS messages received from remote nodes. This can be used effectively when the remote node is a device such as a personal computer and IP addresses are dynamically changed by a method such as DHCP.

Example

When FINS Command is Sent
FINS node number
	IP address table
FINS node		IP address
Node number in number
		153.214.0.62
IP address table	18			IP address
	20	153.214.0.129	IP address
				method
	23	153.218.51.8	FINS command
			sent
Node number not	Network number: xx.xx.00.00
in IP address table
		+	IP address
Automatic	FINS node number: xx
			(See note.)
generation			FINS command
method			sent	Automatic
When FINS Command is Received				generation
FINS node number				method
				(dynamic)
Node number
	Internal table
not in IP
address table	25	153.218.51.10	IP address
Changed			153.218.51.10

FINS response returned

Note When an internal table IP address has been changed with the reception of a FINS command, this is sent to the IP address in the internal table.

Prohibiting Dynamically Changing Remote IP Addresses

For Ethernet Units with Unit Ver. 1.3 or later, methods used to dynamically change remote IP addresses (automatic generation, IP address table, or com- bined (mixed) method) can be prohibited (protected against). Use the CX-Pro- grammer unit setting function (version 5.0 and higher) or Web function setting window to make this setting.

When dynamically changing remote (destination) IP addresses is prohibited, the internal table for each method is maintained in the state when the power was turned ON or restarted. Therefore, protection can be provided against access using FINS/UDP from personal computers or other devices that have dynamically changing IP addresses. To prohibit (protect from) dynamic changes, deselect the Change Dynamically option in the Setup Tab of the Unit Setup.

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